TEHRAN, Iran – Fellow Iranian hard-liners stepped up pressure on President Mahmoud Ahmadinejad on Friday to obey the supreme leader's order to dismiss his top deputy, warning that continued defiance would undermine his legitimacy and alienate his supporters.

The deepening rift between Ahmadinejad and other hard-liners comes at a precarious time for the president since he needs their support against opposition claims that his victory in last month's election was marred by massive fraud.

Hundreds of hard-line students took to the streets of Tehran on Friday, calling on Ahmadinejad to remove Esfandiar Rahim Mashai from the post of first vice president. Mashai, whose daughter is married to the president's son, angered conservatives last year when he made friendly comments toward Israel.

Supreme Leader Ayatollah Ali Khamenei, who has supported Ahmadinejad in the election dispute, ordered the president to remove Mashai earlier this week. But Ahmadinejad has pleaded for more time to explain his reasons for choosing a man he has described as a "pious, caring, honest and creative caretaker for Iran."

But in a step that could force Ahmadinejad's hand, Khamenei's order for dismissal was read on state television and published on the official news agency IRNA for the first time Friday.

"The appointment of Mr. Esfandiari Rahim Mashai the post of vice president is contrary to the interests of you and the government and causes a rift and disillusionment among your supporters. The aforementioned appointment must be canceled and consider it null and void," read the terse letter, which was dated Monday, two days before Ahmadinejad made his public defenses of Mashai.

Previously, word of Khamenei's order had appeared only in semi-official news agencies, leaked by hard-line officials. That gave the president a margin to act as if the order were not definitive, even if he had already received it in private.

Releasing the letter dramatically increases the pressure on Ahmadinejad, and further refusal to act would amount to a flagrant and public defiance of the supreme leader.

Hard-liners made clear they have run out of patience.

"Now that he (Khamenei) has expressed his opinion, there is no room for delay anymore," Ayatollah Ahmad Khatami said during the main Friday prayer sermon in Tehran. "Legitimacy of all in the Islamic system rests with Vali-e-Faqih (the supreme leader)."

Khamenei has the final say over all state matters and has rarely faced defiance in the past. That changed following last month's election when supporters of opposition leader Mir Hossein Mousavi challenged Khamenei's ruling that the June 12 vote was fair.

The flap over the vice presidency appears to signal a move by Khamenei to entrench for himself an even more unquestionable status in the face of the reformist threat. By demanding Mashai's removal, Khamenei is effectively appropriating a new power, since normally the supreme leader does not intervene openly to remove a government official, though he is believed to often vet appointments behind the scenes.

Ahmadinejad's resistance of the order is even more remarkable because Khamenei has been one of the president's key supporters ever since he was first elected in 2005.

Hard-line cleric Jafar Shajooni said Ahmadinejad would alienate his conservative base unless he immediately dismissed Mashai.

Hard-liners "don't tolerate defiance of the supreme leader's views," the semi-official Fars news agency quoted him as saying.

The president may be digging in because he fears an attempt by hard-liners to dictate the government he is due to form next month.

Vali Esmaili, a hard-line lawmaker, said in remarks posted on conservative Web sites that Ahmadinejad will face opposition from the conservative-dominated parliament over his Cabinet appointments unless he dismisses Mashai. The parliament must approve each of the appointments when the government is formed next month.

Mashai angered hard-liners in 2008 when he said Iranians were "friends of all people in the world — even Israelis." He was serving as vice president in charge of tourism and cultural heritage at the time.

Iran has 12 vice presidents, but the first vice president is the most important because he succeeds the president if he dies, is incapacitated, steps down or is removed. The first vice president also leads Cabinet meetings in the absence of the president.

Hard-line students protesting in the streets Friday warned Ahmadinejad that they will withdraw their support unless he dismisses Mashai.

"Obeying the leader's order is the demand of the nation," they chanted.